10 Questions -- No. 9: How key is Dice-K?

Part 9 of a 10-day series on Red Sox questions that will be answered during spring training.

BOSTON -- If you have any doubts about why the Red Sox held on to Daisuke Matsuzaka, you need only look at the Yankees, where GM Brian Cashman appears to have assembled a starting rotation by the pound.

Uncertain of Andy Pettitte's intentions before he officially scheduled his retirement announcement for Friday, Cashman is scrambling to fill out the back end of his rotation. In recent days, he has signed damaged heavyweights Bartolo Colon and Freddy Garcia, former prime-timers whose belt lines have expanded dramatically along with their ERAs.

One Twitter user wondered if Cashman had signed Colon -- who in 2008 rolled into Red Sox camp and made a total of seven starts before breaking down -- or harpooned him. Garcia, who won a World Series with the White Sox in 2005, is listed at 6-foot-4, 250 pounds, which means he’s still spotting incumbent ace CC Sabathia about 50 pounds. Joba Chamberlain, meanwhile, falls somewhere in between, which matches his role on the Yankees’ staff at the moment.

So having Matsuzaka, even if he has not proven to be the transformative pitcher the Sox envisioned when they signed him prior to the 2007 season, still has value, given the shortage of quality arms around. No one, least of all Matsuzaka, imagined a fall this precipitous, from Japanese megastar to Boston bit player. That characterization may sound harsh, but think about it: Red Sox hopes of winning another World Series are far more dependent on the continued excellence of Jon Lester and Clay Buchholz, and bounce-back years from Josh Beckett and John Lackey, than they are on Matsuzaka, who comes into camp as no better than the team’s No. 5 starter.

It was telling this week that manager Terry Francona said new pitching coach Curt Young had not yet made contact with Matsuzaka. Even if the disconnect was for logistical reasons, as Francona said, that’s a drastic change from the heady days when former pitching coach John Farrell was studying Japanese to prepare for Matsuzaka’s arrival.

Matsuzaka is only 30, and he’s coming into camp without his conditioning being an issue, which was not the case the last two seasons. The Sox became so fed up in 2009 that they exiled him to Fort Myers in midseason for what in essence became a second round of spring training, then compelled him to undergo a rigorous conditioning program last winter.

Matsuzaka complied, only to hurt his back before camp opened. He was so far behind the other starters that the Sox had no choice but to put him on the DL for a chance to build up arm strength (the official reason given was a neck strain). He missed the first 23 games, then went back on the DL in June with a strained forearm. He missed one more start in late August with a sore back.

In the midst of all the injuries, his performance remained as maddening as ever. At his best, he was unhittable, as he demonstrated by taking a no-hitter into the eighth inning against the Phillies on May 22. More often, there were too many walks (74 in just 153 2/3 innings), too many high pitch counts, too many abbreviated outings. Matsuzaka won just 9 games, a 6.31 ERA in his last six starts preventing him from reaching double figures in wins.

"I thought last year was the first year he pitched better than his numbers indicated," Sox GM Theo Epstein said this week. "His stuff was better than his numbers indicated. That gives us a little reason for optimism going forward. If he can approximate next year what he did either of his first two years, we'll be quite happy."

According to FanGraphs, Matsuzaka’s fastball did bump up back over 92 mph on average, where it hadn’t been since his first season. And he held opposing batters to a .235 batting average. And his pride has clearly been challenged the last two years, leaving him plenty of incentive.

But even if Matsuzaka falters, the Sox have options. Tim Wakefield is back for a last hurrah, and Felix Doubront is waiting in the wings. The Sox would love to see 30 starts and 180-plus innings from Daisuke. But the success of their season doesn’t hinge on how he pitches.

How important a part of the rotation is Matsuzaka, in your opinion?

Coming Friday: With the emergence of Jon Lester/Clay Buchholz, how much bounce-back do the Sox need from John Lackey/Josh Beckett?